When Pan Am started its trans-pacific air mail service in the 1930s, some of their China Clipper aircrewmen were experienced nautical navigators. These men brought a unique line-crossing ceremony to the flying boats between the United States and New Zealand and Australia. Passengers crossing the equator for the first time were required to provide a dollar bill to be endorsed by those who had made the passage before. The endorsed bill, known as a “short-snorter note”, was returned to the initiate as a credential for future line-crossing ceremonies. The tradition continued on flying boats operated for the United States Navy through the second world war.